Individual foraging site fidelity in lactating New Zealand fur seals : Continental shelf vs. oceanic habitats

Wide-ranging marine central place foragers often exhibit foraging site fidelity to oceanographic features over differing spatial scales (i.e., localized coastal upwellings and oceanic fronts). Few studies have tested how the degree of site fidelity to foraging areas varies in relation to the type of ocean features used. In order to determine how foraging site fidelity varied between continental shelf and oceanic foraging habitats, 31 lactating New Zealand fur seals (Arctocephalus australis forsteri1) were satellite tracked over consecutive foraging trips (14–108 d). Thirty-seven foraging trips were recorded from 11 females that foraged on the continental shelf, in a region associated with a coastal upwelling, while 65 foraging trips were recorded from 20 females that foraged in oceanic waters. There were no significant differences in the mean bearings (to maximum distance) of individual's consecutive foraging trips, suggesting individual fidelity to foraging areas. However, overlap in area and time spent in area varied considerably between continental shelf and oceanic foragers. Females that foraged on the continental shelf had significantly greater overlap in consecutive foraging trips when compared to females that foraged in oceanic waters (overlap in 5 × 5 km grid cells visited on consecutive trips 55.9%± 20.4% and 13.4%± 7.6%, respectively). Females that foraged on the continental shelf also spent significantly more time within the same grid cell than females that foraged in oceanic waters (maximum time spent in 5 × 5 km grid cells: 14%± 5% and 4%± 2%, respectively). This comparatively high foraging site fidelity may reflect the concentration of productivity associated with a coastal upwelling system, the Bonney Upwelling. Lower foraging site fidelity recorded by seals that foraged in oceanic waters implies a lower density/larger scale habitat, where prey are more dispersed or less predictable at fine scales, when compared to the continental shelf region.

Vitamin D and health in pregnancy, infants, children and adolescents in Australia and New Zealand: a position statement.

The recommended level for serum 25-hydroxyvitamin D (25(OH)D) in infants,  children,  dolescents and during pregnancy and lactation is ≥ 50 nmol/L. This level may need to be 10-20 nmol/L higher at the end of summer to maintain levels ≥ 50 nmol/L over winter and spring. • Sunlight is the most important source of vitamin D. The US recommended dietary allowance for vitamin D is 600 IU daily in children aged over 12 months and during pregnancy and lactation, assuming minimal sun exposure. • Risk factors for low vitamin D are: lack of skin exposure to sunlight, dark skin, southerly latitude, conditions affecting vitamin D metabolism and storage (including obesity) and, for infants, being born to a mother with low vitamin D and exclusive breastfeeding combined with at least one other risk factor. • Targeted measurement of 25(OH)D levels is recommended for infants, children and adolescents with at least one risk factor for low vitamin D and for pregnant women with at least one risk factor for low vitamin D at the first antenatal visit. • Vitamin D deficiency can be treated with daily low-dose vitamin D supplements, although barriers to adherence have been identified. High-dose intermittent vitamin D can be used in children and adolescents. Treatment should be paired with health education and advice about sensible sun exposure. Infants at risk of low vitamin D should be supplemented with 400 IU vitamin D₃ daily for at least the first year of life. • There is increasing evidence of an association between low vitamin D and a range of non-bone health outcomes, however there is a lack of data from robust randomised controlled trials of vitamin D supplementation.